Commit Graph
12649 Commits
Author SHA1 Message Date
Ian Jackson 62b4d4769c libxl: Fix NULL pointer due to XSA-178 fix wrong XS nodename
In "libxl: Do not trust backend for disk eject vdev" (c69871a2fb on
xen.git#staging) we changed libxl_evenable_disk_eject to read the
device vdev out of xenstore from the /libxl path, rather than the
backend path, and to read it during setup rather than on each event.

However, the patch has a mistake:
    -        GCSPRINTF("%s/dev", backend), NULL);
    +        GCSPRINTF("%s/vdev", libxl_path), &configured_vdev);
                           ^
Spot the extra "v".  This causes configured_vdev always to be NULL.
configured_vdev is passed to [libxl__]strdup.

In Xen 4.6 and later libxl__strdup is used and tolerates NULL.
evg->vdev is set to NULL.  This propagates to the `vdev' field in the
generated event.  This may or may not cause further trouble, depending
on the calling application.  In our osstest test cases it does not
cause any trouble, so the bug goes undetected.

In Xen 4.5 and earlier, the strdup does not tolerate NULL, and libxl
crashes immediately.  This has been detected by osstest as a
regression in Xen 4.5.

IMO this patch should be applied immediately to
  xen.git#staging-4.5 (to check that it fixes the osstest regression)
  xen.git#staging     (to check that it does not break master

Subject to passes, it should then be propagated to all supported
stable trees and also be mentioned in an update to XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
CC: security@xenproject.org
CC: Jan Beulich <jbeulich@suse.com>
CC: Wei Liu <wei.liu2@citrix.com>
(cherry picked from commit 27c5d7ff8cfdc2e15ff521b4912d69b782a269d7)
2016-06-08 16:13:24 +01:00
Haozhong Zhang e63888627a x86/mce: handle reserved domain ID in XEN_MC_msrinject
Commit 26646f3 "x86/mce: translate passed-in GPA to host machine
address" and commit 4ddf474 "tools/xen-mceinj: Pass in GPA when
injecting through MSR_MCI_ADDR" forgot to consider reserved domain
ID and mistakenly add MC_MSRINJ_F_GPADDR flag for them, which in turn
causes bug reported by
http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg02640.html.

This patch removes MC_MSRINK_F_GPADDR flag and checks this when injecting
to reserved domain IDs except DOMID_SELF, and treats the passed-in
address as host machine address.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christoph Egger <chegger@amazon.de>
2016-06-08 11:08:55 +02:00
Chris Patterson c2a17869d5 libfsimage: replace deprecated readdir_r() with readdir()
Replace the usage of readdir_r() with readdir() to address a
compilation error under glibc due to the deprecation of readdir_r
for their next release (2.24) [1, 2].

Add new error checking on readdir(), and fail if error occurs.

--

From the GNU libc manual [3]:
"
 It is expected that future versions of POSIX will obsolete readdir_r and
 mandate the level of thread safety for readdir which is provided by the
 GNU C Library and other implementations today.
"

There is a filed bug in the Austin Group Defect Tracker [4]  in which 'dalias'
proposes (in comment 0001632) that:
"
   I would like to propose an alternate solution. For readdir, replace the text:
    "The readdir() function need not be thread-safe."
   with:
    "If multiple threads call the readdir() function with the same directory
    stream argument and without synchronization to preclude simultaneous
    access, then the behavior is undefined."

   With this change, the clunky readdir_r function is no longer needed or
   useful, and should probably be deprecated. As the only reasonable way
   to meet the implementation requirements for readdir is to have the dirent
   buffer in the DIR structure, this change should not require any change to
   existing implementations.
"

[1] https://sourceware.org/ml/libc-alpha/2016-02/msg00093.html
[2] https://sourceware.org/bugzilla/show_bug.cgi?id=19056
[3] https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html
[4] http://austingroupbugs.net/view.php?id=696

Signed-off-by: Chris Patterson <pattersonc@ainfosec.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-06-03 18:11:55 +01:00
Chris Patterson b9daff9d81 libxl: replace deprecated readdir_r() with readdir()
Replace the usage of readdir_r() with readdir() to address a
compilation error under glibc due to the deprecation of readdir_r
for their next release (2.24) [1, 2].

Remove code specific to usage of readdir_r which is no longer required,
such as zalloc_dirent().

--

From the GNU libc manual [3]:
"
 It is expected that future versions of POSIX will obsolete readdir_r and
 mandate the level of thread safety for readdir which is provided by the
 GNU C Library and other implementations today.
"

There is a filed bug in the Austin Group Defect Tracker [4]  in which 'dalias'
proposes (in comment 0001632) that:
"
   I would like to propose an alternate solution. For readdir, replace the text:
    "The readdir() function need not be thread-safe."
   with:
    "If multiple threads call the readdir() function with the same directory
    stream argument and without synchronization to preclude simultaneous
    access, then the behavior is undefined."

   With this change, the clunky readdir_r function is no longer needed or
   useful, and should probably be deprecated. As the only reasonable way
   to meet the implementation requirements for readdir is to have the dirent
   buffer in the DIR structure, this change should not require any change to
   existing implementations.
"

[1] https://sourceware.org/ml/libc-alpha/2016-02/msg00093.html
[2] https://sourceware.org/bugzilla/show_bug.cgi?id=19056
[3] https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html
[4] http://austingroupbugs.net/view.php?id=696

Signed-off-by: Chris Patterson <pattersonc@ainfosec.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-06-03 18:11:48 +01:00
Konrad Rzeszutek Wilk 32df791797 xen: Rename of xSplice to livepatch.
Specifically:

s/\.xsplice/\.livepatch/
s/XSPLICE/LIVEPATCH/
s/xsplice/livepatch/
s/livepatch_patch_func/livepatch_func/
s/xSplice/Xen Live Patch/
s/livepatching/livepatch/
s/arch_livepatch_enter/arch_livepatch_quiesce/
s/arch_livepatch_exit/arch_livepatch_revive/

And then modify some of the function arguments
to have two more characters.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:10:28 -04:00
Ian Jackson 03273df2ec libxl: Cleanup: use libxl__backendpath_parse_domid in libxl__device_disk_from_xs_be
Rather than an open-coded sscanf.  No functional change with correct
input.

This is a followup to XSA-175 and XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 16:35:02 +01:00
Ian Jackson 624c862176 libxl: Cleanup: Have libxl__alloc_vdev use /libxl
When allocating a vdev for a new disk, look in /libxl/device, rather
than the frontends directory in xenstore.

This is more in line with the other parts of libxl, which ought not to
trust frontends.  In this case, though, there is no security bug prior
to this patch because the frontend is the toolstack domain itself.

If libxl__alloc_vdev were ever changed to take a frontend domain
argument, this patch will fix a latent security bug.

This is a followup to XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 16:34:58 +01:00
Ian Jackson 2538aaa238 libxl: Do not trust backend for vusb
Read the type from /libxl, rather than the backend.  (We still trust
the backend for details such as the number of ports, etc.; these are
not a security problem.)

In getinfo, use the computed frontend path, and the incoming domid,
rather than needlessly reading these values from the backend.

This is part of XSA-178.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
---
v2: New patch following rebase.
2016-06-02 15:53:29 +01:00
Ian Jackson 4f79473898 libxl: Do not trust backend in channel list
Read the name from /libxl/device.  Pass the /libxl path to
libxl__device_channel_from_xenstore.

This removes the final route by which READ_LIBXLDEV might receive a
backend path.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
---
v2: Remove be_path variable which is now no longer used.
2016-06-02 15:53:29 +01:00
Ian Jackson f7653d0d15 libxl: Do not trust backend for nic in list
libxl_device_nic_list should use the /libxl path to search for
devices, and for obtaining the device information.

The "type" parameter was always "vif".  Abolish it.  (In any case,
paths in /libxl/device are named after the frontend type which is
constant, not the backend type which might in future vary.)

Abolish a redundant store to pnic->backend_domid.  Before this commit,
that store was not needed because libxl_device_nic_init (called by
libxl__device_nic_from_xenstore) would zero it.  Now it overwrites the
correct backend domid with zero; so remove it.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 6fd0b1574e libxl: Do not trust backend for nic in devid_to_device
libxl_devid_to_device_nic should read the information it needs from
the /libxl/device path, not the backend.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 922b354718 libxl: Do not trust backend in nic getinfo
This is part of XSA-178.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 478bccdc9e libxl: Have READ_LIBXLDEV use libxl_path rather than be_path
Fix the just-introduced bug in this macro: now it reads the
trustworthy libxl_path.  Change the variable name in the two functions
(nic and channel) which use it.

Shuffling the bump in the carpet along, we now introduce three new
bugs: the three call sites pass a backend path where a frontend path
is expected.

No functional change.

This is part of XSA-178.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 83e679c0e3 libxl: Rename READ_BACKEND to READ_LIBXLDEV
We are going to want to change all the functions that use READ_BACKEND
to get untrustworthy information from the backend, to use trustworthy
information from /libxl.

This will involve replacing READ_BACKEND, which reads from be_path,
with a similar macro READ_LIBXLDEV, which reads from libxl_path.

The macro name change generates a lot of clutter in the diff.  So we
break it out into this separate patch.  Here, we rename the macro, but
the implementation does not really match the new name.

So, another way to look at this, is that we have transformed the bug:
 * All of the backends use READ_BACKEND, which is unsafe
into the new bug:
 * READ_LIBXLDEV actually reads be_path, which is unsafe.

There is no functional change as yet.

This is part of XSA-178.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 94a3e2798e libxl: Rename libxl__device_{nic,channel}_from_xs_be to _from_xenstore
We are going to change these functions to expect, and be passed, a
/libxl path.  So it is wrong that they are called _from_xs_be.

Neither function reads anything which isn't found in both places, so
we can and will change the call sites later.

The only remaining function in libxl called *_from_xs_be relates to
PCI devices, for which the backend domain is hardcoded to 0 throughout
the libxl_pci.c.

No functional change.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson b3a4560e96 libxl: Do not trust backend for channel in getinfo
Do not read the frontend path out of the backend.  We have it in our
hand.  Likewise the guest (frontend) domid was one of our parameters (!)

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 3cc74772fd libxl: Do not trust backend for cdrom insert
Use the /libxl path where appropriate.  Rename `path' variable to
`be_path' to make sure we caught all the occurrences.

Specifically, when checking that the device still exists, check the
`frontend' value in /libxl, rather than anything in the backend
directory.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 29225b2973 libxl: Do not trust backend for disk in getinfo
Do not read the frontend path out of the backend.  We have it in our
hand.  Likewise the guest (frontend) domid was one of our parameters (!)

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson e4a4a84957 libxl: Do not trust backend for disk; fix driver domain disks list
Rework libxl__device_disk_from_xs_be (which takes a backend path) into
to libxl__device_disk_from_xenstore (which takes a libxl path).

libxl__device_disk_from_xenstore now finds the backend path itself,
although it doesn't use it any more for most of its functions.  We
rename the variable from be_path to backend_path to make sure we
didn't miss any cases.

All the data collection is now done by reading from the copy in
/libxl.

libxl_device_disk_list and its helper libxl__append_disk_list (which
used to be libxl__append_disk_list_of_type) need extensive rework,
because they now need to specify the /libxl path rather than the
backend path.

To do that they enumerate disks by looking in the appropriate area in
/libxl.  Previously they scanned various of the backend directories in
dom0 (which was broken for driver domains).  It is no longer necessary
to enumerate the various disk backends, because they all use the same
paths in /devices.  libxl__device_disk_from_xenstore will parse the
type out of the backend path, for itself.  (Indeed, it did so before -
the now-gone type parameter to libxl__append_disk_list_of_type wasn't
used other than to construct the directory to list.)

Finally, remove a redundant store to pdisk->backend_domid in
libxl__append_disk_list[_of_type].  Even before this commit, that
store was not needed because libxl_device_disk_init (called by
libxl__device_disk_from_xenstore) would zero it.  Now it overwrites
the correct backend domid with zero; so remove it.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
---
v2: Also fix up COLO reads, following rebase
2016-06-02 15:53:29 +01:00
Ian Jackson c69871a2fb libxl: Do not trust backend for disk eject vdev
For disk eject, use configured vdev from /libxl, not backend.

The backend directory is writeable by driver domains.  This means that
a malicious driver domain could cause libxl to see a wrong vdev,
confusing the user or the toolstack.

Use the vdev from the /libxl space, rather than the backend.

For convenience, we read the vdev from the /libxl space into the evg
during setup and copy it on each event, rather than reading it afresh
each time (which would in any case involve generating or saving a copy
of the relevant /libxl path).

This is part of XSA-178.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 3a5fec0379 libxl: cdrom eject and insert: write to /libxl
Copy the new type and params values to /libxl, so that the information
in /libxl is kept up to date.

This is needed so that we can return this trustworthy information,
rather than trusting the backend-writeable parts of xenstore.

This is part of XSA-178.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 78feb516f3 libxl: Do not trust backend for vtpm in getinfo (uuid)
Use uuid from /libxl, rather than from backend.  I think the backend
is not supposed to change the uuid, since it seems to be set by libxl
during setup.

If in fact the backend is supposed to be able to change the uuid, this
patch needs to be dropped and replaced by a patch which makes the vtpm
uuid lookup tolerate bad or missing data.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 615c2be2ff libxl: Do not trust backend for vtpm in getinfo (except uuid)
* Do not check the backend for existence.  We have already read the
  /libxl path so know that the vtpm exists (or is supposed to); if the
  backend doesn't exist then that must be the backend's doing.
* Get the frontend path from the /libxl directory.
* The frontend domid is the guest domid, and does not need to be read
  from xenstore (!)

We still attempt to read the uuid from the backend.  This will be
fixed in the next patch.

This is part of XSA-178.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson 696a1c5e8e libxl: Do not trust backend in libxl__device_exists
To determine whether a device is supposed to exist, look in /libxl,
rather than the backend.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:29 +01:00
Ian Jackson deffd3cc8a libxl: Make copy of every xs backend in /libxl in _generic_add
We want to stop libxl trustingly reading information from the backend
directory (since this is, of course, writeable by the backend, which
might be a semi-trusted driver domain).

In principle it is wrong in current libxl for anything to try to
divine virtual device configuration from xenstore: the JSON domain
config ought to supply that, and xenstore should only tell us which
devices actually exist.

However:

Firstly, there are several existing places where configuration
information is retrieved from xenstore rather than JSON.  We do not
want to reen gineer this in a security patch.

Secondly, we want to make a security patch which can be backported to
versions of libxl without the JSON configuration machinery.

So we take the expedient approach of keeping a copy of the
configuration somewhere we trust, namely /libxl.  This is obviously
fairly low-risk, although it does write significantly more keys in
xenstore.

In this patch we make this change in libxl__device_generic_add.  This
is responsible for actually writing the vast majority of device
information to xenstore.  There are a few loose ends which will be
dealt with in a moment.

Likewise, changes to readers to use the new location will appear in
further patches.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson 03814de1d2 libxl: Do not trust frontend for vusb
Do not use the frontend directory for enumerating the vusb devices;
since the frontend could delete them, this could result in devices
being lost and not torn down, etc.  Instead, use the /libxl directory
for enumeration.  So:

* Replace vusb_be_from_xs_fe with vusb_be_from_xs_libxl
* Change the call sites
* Change various places that use the dompath to use libxl_dom_path
* Rename some `path' variables appropriate (to spot any missed updates)
* Parse backend domid out of backend path rather than reading it from
  the frontend (several places)

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
---
v3: Whitespace adjustment to parameter list indentation
v2: New patch, following rebase
2016-06-02 15:53:28 +01:00
Ian Jackson 89ef5dbc16 libxl: Do not trust frontend for channel in getinfo
libxl_device_channel_getinfo needs to examine devices without trusting
frontend-controlled data.  So:

* Use /libxl to find the backend path.
* Parse the backend path to find the backend domid, rather than
  reading it from the frontend.
* Tolerate FRONTEND/tty vanishing.

Note that there is a strange off-by-one error in the computation of
both fe_path and libxl_path in libxl_device_channel_getinfo: the
incoming channel->devid, which is copied to channelinfo->devid, has +1
applied to calculate the frontend path (and, after this patch, the
libxl path).  I.e., the devid passed to libxl_device_channel_getinfo
must be one less than the actual devid for the device being asked
about.

This is actually a bug which mirrors a bug in
libxl__append_channel_list, which fills in the devids of the channel
devices it finds with sequentially increasing numbers starting at 0.

In the usual case channels have real devids starting at 1 (because
there is the console, which is devid 0, but not a channel).  So these
bugs usually cancel out.

We do not address this problem at this time.  This bug does not have
any security implications.

This patch is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson ca04e01490 libxl: Do not trust frontend for channel in list
libxl_device_channel_list should not trust frontend-provided data.

So it needs to iterate using the /libxl paths, and read the backend
path out of /libxl.

However, it also filters out pure "consoles", which are channels
without a "name".  But the name was stored only in the frontend
directory, which the frontend can delete.

So store the name in the backend too.  (Ideally we would store it in
/libxl, where the backend can't write to it either, but
libxl__device_console_add not currently have access to the xenstore
transaction used by libxl__device_generic_add.  Protection against the
backend will come later, in XSA-178.)

Because the libxl paths are defined to be in terms of the frontend
device types, not the backend device types, it is no longer correct
for libxl__append_channel_list to take a type argument.  Abolish this
(with no functional effect).

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson eaccadee01 libxl: Do not trust frontend for nic in getinfo
libxl_device_nic_getinfo needs to examine devices without trusting
frontend-controlled data.  So:

* Use /libxl to find the backend path.
* Parse the backend path to find the backend domid, rather than
  reading it from the frontend.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson 7e03b128e0 libxl: Do not trust frontend for nic in libxl_devid_to_device_nic
Find the backend by reading the pointer in /libxl rather than in the
guest's frontend area.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson 0dbc6af04f libxl: Do not trust frontend for vtpm in getinfo
libxl_device_vtpm_getinfo needs to examine devices without trusting
frontend-controlled data.  So:

* Use /libxl to find the backend path.
* Parse the backend path to find the backend domid, rather than
  reading it from the frontend.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson 0527125a6a libxl: Do not trust frontend for vtpm list
libxl_device_vtpm_list needs to enumerate and identify devices without
trusting frontend-controlled data.  So

* Use the /libxl path to enumerate vtpms.
* Use the /libxl path to find the corresponding backends.
* Parse the backend path to find the backend domid.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson c429d90b6d libxl: Do not trust frontend for disk in getinfo
* Rename the frontend variable to `fe_path' to check we caught them all
* Read the backend path from /libxl, rather than from the frontend
* Parse the backend domid from the backend path, rather than reading it
  from the frontend (and add the appropriate error path and initialisation)

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson e4dccc73a3 libxl: Do not trust frontend for disk eject event
Use the /libxl path for interpreting disk eject watch events: do not
read the backend path out of the frontend.  Instead, use the version
in /libxl.  That avoids us relying on the guest-modifiable
$frontend/backend pointer.

To implement this we store the path
  /libxl/$guest/device/vbd/$devid/backend
in the evgen structure.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson f9a7931b0d libxl: Do not trust frontend in libxl__device_nextid
When selecting the devid for a new device, we should look in
/libxl/device for existing devices, not in the frontend area.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson e3d851340c libxl: Do not trust frontend in libxl__devices_destroy
We need to enumerate the devices we have provided to a domain, without
trusting the guest-writeable (or, at least, guest-deletable) frontend
paths.

Instead, enumerate via, and read the backend path from, /libxl.

The console /libxl path is regular, so the special case for console 0
is not relevant any more: /libxl/GUEST/device/console/0 will be found,
and then libxl__device_destroy will DTRT to the right frontend path.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson 481dddb63b libxl: Provide libxl__backendpath_parse_domid
Multiple places in libxl need to figure out the backend domid of a
device.  This can be discovered easily by looking at the backend path,
which always starts /local/domain/$backend_domid/.

There are no call sites yet.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-02 15:53:28 +01:00
Ian Jackson 811b188add libxl: Record backend/frontend paths in /libxl/$DOMID
This gives us a record of all the backends we have set up for a
domain, which is separate from the frontends in
  /local/domain/$DOMID/device.

In particular:

1. A guest has write permission for the frontend path:
  /local/domain/$DOMID/device/$KIND/$DEVID
which means that the guest can completely delete the frontend.
(They can't recreate it because they don't have write permission
on the containing directory.)

2. A guest has write permission for the backend path recorded in the
frontend, ie, it can write to
  /local/domain/$DOMID/device/$KIND/$DEVID/backend
which means that the guest can break the association between
frontend and backend.

So we can't rely on iterating over the frontends to find all the
backends, or examining a frontend to discover how a device is
configured.

So, have libxl__device_generic_add record the frontend and backend
paths in /libxl/$DOMID/device, and have libxl__device_destroy remove
them again.

Create the containing directory /libxl/GUEST/device in
libxl__domain_make.  The already existing xs_rm in devices_destroy_cb
will take care of removing it.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
---
v2: Correct actual path computation (!)
v3: Correct actual path computation - really this time (!)
2016-06-02 15:53:28 +01:00
Vitaly Kuznetsov 7e81d992b1 libxl: keep PoD target adjustment by memory fudge after reload_domain_config()
Commit 56fb5fd623 ("libxl: adjust PoD target by memory fudge, too")
introduced target_memkb adjustment for HVM PoD domains on create,
wherein the value it wrote to target is always 1MiB lower than the
actual target_memkb.  Unfortunately, on reboot, it is this value which
is read *unmodified* to feed into the next domain creation; from which
1MiB is subtracted *again*.  This means that any guest which reboots
with memory < maxmem will have its memory target decreased by 1MiB on
every boot.

This patch makes it so that when reading target on reboot, we adjust the
value we read *up* by 1MiB, so that the domain will be build with the
appropriate amount of memory and the target will remain the same after
reboot.

This is still not quite a complete fix, as the 1MiB offset is only
subtracted when creating or rebooting; it is not subtracted when 'xl
set-memory' is called.  But it will prevent any situations where memory
is continually increased or decreased.  A better fix will have to wait
until after the release.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-06-01 17:26:33 +01:00
Wei Liu 5ff371e9d8 Revert "x86/mce: handle reserved domain ID in XEN_MC_msrinject"
This reverts commit 55dc7f6126.

The get_maintainer.pl script showed Jan as the maintainer so I pushed
this patch. But in fact according to MAINTAINERS file, he's not.  Revert
this patch and wait until a maintainer acks it.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
2016-05-27 17:18:47 +01:00
Haozhong Zhang 55dc7f6126 x86/mce: handle reserved domain ID in XEN_MC_msrinject
Commit 26646f3 "x86/mce: translate passed-in GPA to host machine
address" and commit 4ddf474 "tools/xen-mceinj: Pass in GPA when
injecting through MSR_MCI_ADDR" forgot to consider reserved domain
ID and mistakenly add MC_MSRINJ_F_GPADDR flag for them, which in turn
causes bug reported by
http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg02640.html.

This patch removes MC_MSRINK_F_GPADDR flag and checks this when injecting
to reserved domain IDs except DOMID_SELF, and treats the passed-in
address as host machine address.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-27 16:10:34 +01:00
Wei Liu b0d409d9c4 libxl: set XEN_QEMU_CONSOLE_LIMIT for QEMU
XSA-180 provides a patch to QEMU to bodge QEMU logging issue. We
explicitly set the limit in libxl for 4.7.

Introduce a function for setting the environment variable and call it in
the right places.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-26 17:22:12 +01:00
Wei Liu 80703daf3e xl: use xstrdup in cpurange_parse
This ensures buf is always valid when it is passed to strtok_r.

CID: 1291936

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-25 14:42:35 +01:00
Jan Beulich 4504b7d1a6 libxl: drop stray const from function return type
Some compiler versions warn about this, causing the build to fail due
to -Werror.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-24 16:51:17 +01:00
Wei Liu 116d8bab9b tools: bump library version numbers
The following libraries are checked:
1. libxc, version number bumped
2. libxl, version number bumped
3. libxlu, no development in 4.7 cycle, but depends on libxl, version
   number bumped
4. libs/*, new in 4.7 cycle, version numbers not bumped
5. libxenstore, no development in 4.7 cycle, version number not bumped
6. libxenstat, no development in 4.7 cycle, version number not bumped
7. libvchan, depends on  xengnttab library, API changed, version number
   bumped

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-24 16:26:37 +01:00
Anthony PERARD a11c52af1c libxl: Avoid advertising about device_model_user config option
Running QEMU as non-root user is not ready yet, so replace the warning
with a debug message and remove the option from the man page.

Also improve the doc to include more potential issue with running QEMU
as non-root.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-24 16:26:26 +01:00
Wei Liu 32e9d0f065 libxl: nic type defaults to vif in hotplug for hvm guest
We don't support plugging in emulated nic to a HVM guest.

The "update_json" flag is only set when doing hotplug, so use that as an
indicator in libxl__device_nic_add. The new hotplug flag to _setdefault
function should be false in all other locations.

This then requires saving nic type in JSON file, because we don't want
the receiving end to recalculate the nic type.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-23 14:46:34 +01:00
Wei Liu a396c2549e libxl: consolidate casting to xc psr type to a function
In commit 31268fea (libxl: fix passing the type argument to xc_psr_*),
casting to xc psr type was done at each call site.

This patch consolidates casting into a function to avoid casting at each
conversion point. Each call site remains more type safe.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-19 12:49:59 +01:00
Dario Faggioli 3c0d13d9d1 xenalyze: fix a spurious newline
in dump mode, when tracing context switches.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-19 12:49:22 +01:00
Jim Fehlig d532f45d94 libxl: don't add cache mode for qdisk cdrom drives
qemu commit 91a097e7 forbids specifying cache mode for empty
drives. Attempting to create a domain with an empty qdisk cdrom
drive results in

qemu-system-x86_64: -drive if=ide,index=1,readonly=on,media=cdrom,
   cache=writeback,id=ide-832: Must specify either driver or file

libxl only allows an empty 'target=' for cdroms. By default, cdroms
are readonly (see the 'access' parameter in xl-disk-configuration.txt)
and forced to readonly by any tools (e.g. xl) using libxlutil's
xlu_disk_parse() function. With cdroms always marked readonly,
explicitly specifying the cache mode for cdrom drives can be dropped.
The drive's 'readonly=on' option can also be set unconditionally.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2016-05-15 16:07:32 +01:00